1. Field of the Invention
The present invention relates to a fluorine-containing block copolymer and an artificial lens comprising the same. More particularly, the present invention relates to a fluorine-containing block copolymer which comprises at least one soft segment and at least one hard segment and an artificial lens which comprises said block copolymer.
2. Description of the Related Art
An artificial lens made of polymethyl methacrylate (PMMA) is commercially available and used. Since PMMA is a hard resin, an incisure of at least 7 mm length is necessary to insert the PMMA artificial lens in an eye. As the incisure is smaller the distortion of an visual image is smaller after surgery. Therefore, the incisure of at least 7 mm length is not preferable. In case of resurgery for replacing the artificial lens, it is difficult to remove the used artificial lens since many cells adhere to the surface of the PMMA lens. In addition, since a glass transition temperature (T.sub.g) of PMMA is 123.degree. C., it is impossible to sterilize the lens with steam, and the PMMA lens is sterilized with ethylene oxide (EO) gas. However, since residual EO gas tends to cause inflammation, it is necessary to remove the EO gas, but it is troublesome since PMMA easily absorbs the EO gas.
To overcome the above problems of the PMMA artificial crystalline lens, a fluorine-containing block copolymer Daiel Thermo (trade mark) T 530 is proposed. This block copolymer comprises vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene blocks and ethylene/tetrafluoroethylene blocks. However, Daiel Thermo T 530 has a small refractive index of 1.357, its application is limited.